Abstract: A field experiment was carried out to study the effect of optimized nitrogen with supplementary irrigation, straw mulch, combination of organic manure and inorganic fertilizer on the population dynamics and yield of winter wheat. And it was to provide theoretical basis for the cultivation measures of grains yield and resource using efficiency in winter wheat of arid and semiarid areas. The results showed that the population amount of the each treatment were all increased after emergence, reached the highest at revival stage, and decreased afterwards. Before the revival stage, dry biomass was the highest in the conventional farming treatment, while there was no significant difference among all the treatments on the population amount. After the revival stage, significant differences were showed in the population amount and dry biomass; dry biomass was highest in the optimized mode 3 because of topdressing nitrogen and supplementary irrigation in jointing stage. Nitrogen and irrigation could improve the population and dry biomass. The economic benefit showed that the maximum yield was 4500 kg/hm2 in the optimize modes 3 which was 33.4%, 127.8% higher than the conventional farming and control treatment, respectively. The maximum profit was 4537 yuan/hm2 in the optimize modes 3 which was 22.7%, 322.2% higher than farmer mode and control treatment, respectively. In short, under the limited irrigation condition of Weibei dryland, optimized mode 3 could effectively save great amount of water resource , increase the grain yield and profit of winter wheat, so it has a great promotion value.